There is something wrong with the electrical wiring in my house.
A few LED lamps stay on (but dim, with the intensity depending on the location of the lamp) even when off.
In addition, I sometimes get shocked by my laptop case. The shocks seem to start every day at 7 PM. When my laptop case starts "leaking" electricity (that's how I interpret the shocks), the LEDs seem to be completely off. There is no equipment that I can think of in the house that would automatically turn on or off at 7 PM.
There's also a CFL that sometimes flashes with the switch off, if all this wasn't weird enough.
Can anyone explain what's going on and help fix it?
The ground rod was changed recently, I had the grounding tested and it works fine (though I'll admit I only tested one socket, so it's possible that the socket the laptop is usually connected to is not grounded properly).
Edit
I borrowed a socket tester earlier today and I found some interesting things. The socket I plug my laptop in has >20V between the ground and live. To get rid of that voltage and back to around 2/3V, I have to turn off the socket's breaker and that room's lights, which are on a different breaker! Turning just one off I still get the voltage (my tester can't be more precise when over 20V). Also the tester can't get the RCD to break on that socket. It works with other circuits in the house.
In the rest of the house I've measured between 2V and 4V between ground and live in most sockets, one had 10V. These measurements were made with all breakers switched on.
The grid provides 230V at 50hz if it matters.
Edit 2
An electrician will try to fix the issue with the two circuits being mixed up today.
However I've made a discovery. I used a tool that trips RCDs and measures the reaction time. During the day, it works fine around the house (except the above mentioned circuits, but that's a different matter). After 7 pm and until the morning, I cannot trip any RCD in the house with this tool. It's like there's no grounding at all, but only at night!
Best Answer
The tingling is lethal. What saved you was high resistance on the rest of the circuit back to source. This needs to be fixed ASAP.
It might be a leaking, faulty appliance. Plug the appliance into a RCD protected outlet and next time it shocks you, it will instantly trip. Into the trash the appliance goes. If it's a PC, the problem is the power supply or power brick.
I wouldn't worry about the external RCD tester not tripping, that is the normal/correct behavior if the circuit does not have a wired ground. An RCD protected circuit doesn't really need a ground to protect you, just equipment.
Give your grounding system a very thorough once-over
It seems like you are doing everything right and still getting shocks, so the first place I go in that case is the grounding system. It has 3 parts:
the grounding electrode system from the panel to the actual earth. This consists of a fairly hefty ground wire from the panel's ground bar/bus/case to ground rods, Ufer or water pipe connection into the soil. We Americans are fond of two ground rods.
The neutral-ground bond, which connects the ground bus inside the panel to the neutral bus also inside the panel. In America this is often done whimsically, by just landing all the neutrals and grounds on the same busbar. But whatever. It's more useful to have a distinct neutral-ground bond that you can put a clamp meter around.
the equipment safety grounds, which are the "third" ground wires from the panel's ground bus to all your sockets and equipment.
Search all of those, most especially the first two.